Hi Barry, Yes; Seans mechanical design is still likely the very best vertical homebrew. His flat spring setup is quite abit more difficult to make than just using a sprial coil spring; but it could make all the difference in the world. Good food for thought. At one time...Saint Louis University applied, or were going to apply for a patent on that and on his (unknown) tiltmeter. Perhaps, because of the prior public release; it "became" public domain. Regardless; his vertical text and pictures is at: http://www.eas.slu.edu/People/STMorrissey/newtable.html They really limit access on the web site. I was also interested in his tiltmeter; but nobody there followed up after his 2002 death...which is quite strange, as that University had a very long history of seismology. Sean certainly was quite exceptionally very good at his work. Take care, Meredith On Mon, Aug 18, 2008 at 8:37 PM, Barry Lotzwrote: > Meredith > The late STM had a (what I feel ) a good long period vertical design using > hardware store materials (with some help from Macmaster Carr). There is an > adjusting motor which slides a weight for zeroing. I also use a spiral > bimetal spring from a analog themometer to help with daily temperature > deflection drifts. I think others have constructed his design. I have been > very pleased with the results. > Barry > > > > Hi Barry,Yes; Seans mechanical design is still likely the very best vertical homebrew. His flat spring setup is quite abit more difficult to make than just usinga sprial coil spring; but it could make all the difference in the world. Good food for thought.At one time...Saint Louis University applied, or were going to apply for a patent on that and on his (unknown) tiltmeter. Perhaps, becauseof the prior public release; it "became" public domain. Regardless; his vertical text and pictures is at:They really limit access on the web site. I was also interested in his tiltmeter; but nobody there followed up after his 2002 death...which isquite strange, as that University had a very long history of seismology. Sean certainly was quite exceptionally very good at his work.Take care, MeredithOn Mon, Aug 18, 2008 at 8:37 PM, Barry Lotz <barry_lotz@.............> wrote:
MeredithThe late STM had a (what I feel ) a good long period vertical design using hardware store materials (with some help from Macmaster Carr). There is an adjusting motor which slides a weight for zeroing. I also use a spiral bimetal spring from a analog themometer to help with daily temperature deflection drifts. I think others have constructed his design. I have been very pleased with the results.Barry